Brush-holder.



J. F. Mc-ELROY. I

BRUSH HOLDER.

APPLIOATION FILED NOV. 22, 1904.

912,974, Patented Feb. 16, 1909.

F39 'lnvenw viwajwmw 13 mums 'LlrnsJnr. mm WAsnulMo LD c 'aillk whom (itmay concern:

- UNITED srAT PATENT OFFICE- JAMES F. McELROY, or ALBANY, aEwYoRK,ASSIGNOR TO CONSOL'IDATED can HEATING COMPANY. A CORPORATION OF WESTVIRGINIA.

BRUSH-HOLDER.

Application filed November 22, 1904. Serial No. 233.78Bi

B" it' known that I, James F. MoELnoY, a

citizen of the United States, residing at Al-.

bany, county of Albany, State of Xew York,

lia'v e invented certain new and usctul Improvements 111 Brush-Holders,of which the following specification and accompanying drawing illustrateone form of the invention which I now regard as the best out of thevarious forms in which the invention may be embodied.

j "I now proceed to describe my invention, reference belng had to theaccompanying drawing:

Figure 1 is a plan view of my device, Fig.

.2 is a side elevation thereof partly in section.

" In brush holders for dynamo electric ma- 1 chines and motors designedto carry a can bon brush, ditlicultyhasbeen encountered in. 1

making'the necessary electrical connection with the brush, while at thesame time giving it the needful motion involved in its spring bearing onthe commutator' In most x cases the brush is so arranged as to slidefreely in a tubular holder under the influence of its operating spring,while the electrical connection with the brush is made by means of aflexible conductor secured to the brush at one end and attached at itsopposite end to the holder or its supporting stud. Without such flexibleconductor the necessary looseness'of the brush within. its tubularholder prevents the maintenance of a good electrical connection betweensuch holder and the brush.- These flexible. conductors however are alsoopen to objection and'it is my purpose to eliminate them and at the sametime provide for the electrical connection and for the necessarymovementof the brush to and from the commutator in a permanent and reliablemanner. In brief, I provide a pivoted lever which at one endhas jawsadapted to gripthe brush permanently and se- 'curely, so as to maintaina good electrical connection therew th, whlle at its outer end it ispivoted to a conducting support in such manner to be in good electricalconnection therewith. The lever is arched so as to bring its forward endapproximately on a its rear and lower end is pivoted to thesuport'abo'ut on the level of the bearing surace of the brush. The studwhich carries the holder is located between the brush and level withthe. upper edge of the brush, while Specification of Letters Patent.

Patented Feb. 16, 1909.

the pivotal point of thelever and the support to which the lever ispivoted is sleeved upon and insulated from the stud and is provided witha-rearward and downward projection, at the extremity of which the leveraforesaid is pivoted. I also fork both the support and the lever, so asto secure a broad and substantial pivotal base for the lever and alsoinsure the proper electrical connection between the lever and thesupport. I operate the brush holder by means of a spring connected atits upper -endto a link hooke to the lover and'atits lower end anchoredto a. knuckle arranged to be thrown over a dead center to either applythe force of the spring to the lever or to release'it for permitting thelever to be raised, so as to form a break-down anchorage or abutment forthe spring substantially as shown in my Patent; No. 747,890 of December22, 1903. The spring gives an even pressure of the brush against thecommutator in -all positions since as the brush wears away and thespring tends to lose its tension, its leverage on the brush iscorrespondingly increased by the movement of its point of application tothe lever further away from the pivotal point of the lever.

Turning to the drawing, 1 is the carbon brush designed to bear upon thecylindrical surface of a commutator, indicated at 2. -l is the lever ofthe brush holder provided at oneend with jaws 3, 3 between which thebrush 1 may be firmly clamped by means of screws 15, which extendbetween the jaws. passing directly through the orush itself, and drawthe jaws together to grip the brush and establish apermanentand reliableelectrical connection therewith; Moreover the jaws will receive theupper half of the brush and a little more, so that they will clamp thebrush below its middle. This permits the brush to be removed from thejaws when its lower end. has been worn away near to the edges of thejaws and then reversed end for cud o that the. upper half previouslyreceived in the holder may be used in turn upon the commutator. The rearend of the lever is Lt'orkec as shown in Fig. 1 into the two branches10.10 at the extremities of which the lever is pivoted with the axis ofthe pivot at the point 22, approximately on a level with the bearingsurface of the brush Whcre it rests upon the commutator. The

'19, 19 as shown in Fig. 1.

upholding stud 14 projects from a stationary part of the machine in theusual manner and is rectangular in cross section as seen in Fig. 2.

The support upon which. the lever 4 is pivoted is indicated at 5 and isprovided with a sleeve 9 which encircles the stud 14, but is insulatedtherefrom by the insulating sleeve 17. The support is secured inposition 'on the stud by means of screws 25 which are passed downthrough the sleeve into the stud but are insulated by means of bushingsand by the strip of insulating material 18 which lies upon the upperside of the sleeve. From 'the said sleeve the support 5projectsrearwardly and downwardly being -forked into two branches Thesleeve is provided with a binding post 21 to which the leadingin wire isconnected. The respective branches 10 of the lever 4 are pivoted to theextremities of the branches 19 of the support 5 by means of pivots 24which are about on the level of the bearing surface of the brush. Bythis means a good electrical connection is maintained between the leverand its support while a free move ment of the former upon the latter ispermitted.

The operating spring 6 is connected at its upper end to a link 8 whichstraddles a cross rod 27 between the two branches 10, 10 ot' the lever4, being provided with-a screw 12 which passes through the upper side ofthe link and has a grooved end which bears upon-the upper side of thecross rod 27 thereby serving to adjustthe tension of the spring. Thelower end of the spring is connected to a knuckle "(pivoted at 29 on therespectivebranches 19 ot' the support 5 and adapted to be turned fromits full line position, Fig. to its dotted line position,

to release the tension of the spring upon the lever. The tension of thespring being thus relieved the lever, together with the brush carriedatits outer end, may be turned back into the position shown in dottedlines, Fig. 2, where it will be held by the spring 6, which now actsupon the opposite side of the pivotal point a projection 31 on the levercoming against a stop 33 on the support 5.

"By this arrangement a compact form of .br-ush holder is provided, thestud It being close to the commutator 2 and the brush 1, andlli'ttltelllllg' between the brush and the pivotal point of the lever 4.This enables the lever to be ofa sutlicient length to avoid anydeflection of the brushKQl from its normalposition on the commutator asit wears downpthis being also'facilitated by the location-o f 'thepivotal'point 22 approximately on a level with the bearing surface ofthe brush. "I alsohave a reliable electrical connection from the brush'1 through to the binding post 21 to which the leading-hi wire isattached. Moreover, as the brush wears down the pressure of the springtends to increase by reason of a gain in leverage as the lever swingsdown around its point.

What I claim as new and desire to secure by Letters Patent is:

1. A brush holder consisting of a lever having jaws rigid therewith atone end adapted to grip the brush'and make-a good electrical connectiontherewith andpivoted at its opposite end to a support of conduct.- ingmaterial, which support is provided with a binding post for theleading'inwire and projects rearwardly from a stud located between thebrush and the the said lever.-

2. A brush holder consisting of an arched lever having jaws at one endadapted to grip the brush and make a good electrical connectiontherewith and pivoted at its opposite end to the rear extremity of asupport,

to a forked support, which support projectsrearwardly from a studlocated at a point between the brush and the pivotal point of the saidlever, combined with an operating spring acting on anincreasingleverage"as the brush wears away. i 1

4. A brush holder consisting of a lever having jaws at one end which areradial to the commutator and adequate to grip'thc brush and make a goodelectricabconnection therewith and pivoted at its opposite endto asupport, which support is sleeved on. a stud located between the brushand. the pivotal point of the lever and projects rearwardly therefrom,combined with an'operatpivotal point of ing spring acting on anincreasing leverage as the brush wears away; a

A brush holder consisting of an arched lever having jaws at one endadaptedto grip the brush and make agood electrical connection therewithand pivoted atlits opposite end tOjl support, which support is sleevedupon and insulated from a stud located between the brush and the-pivotalpointof the said lever and projectsr'earwardly from the said stud.

6. A brush holder consisting of a lever having jaws at one end adaptedto grip the brush and make" a good electrical connection therewith andpivoted at its rear end to a support of conducting material having abindin post for the leading-in wire, the axis of the pivot being ap)roximately on alevelwith the-bearing surtace of the rush,

b and the'said suplport being carried by ,a

bearing between t bearing surface.

7; A brush holder consisting of an arched lever having jaws at one endada ted to esaid axis and the said 1 grip the brush and make'a good eectrical connection therewith, combined with an upholding stud locatedwithin thearch of the having jaws at one lever'and provided with asupport extending rearwardly andvdownwardly to a point approximately ona level with the bearing therewith and pivoted at its opposite end to asupport, the axis ofthe pivot being approximately on a levelwith thebearing surface of the brush, combined with aspring connected at one endto the said lever and provided with a dead-centered breakdown anchorageor abutment. v

9. A brush holder consisting of an arched lever having jaws at one endadapted to grip the brush and make a good electrlcal connectiontherewith, combined with a support projecting rearwardly and downwardlyfrom a stud located in the arch of the lever and having the leverpivoted to its rear and lower extremities, and an operating spring forthe lever provided with a breakdown anchorage or abutment.

In witness whereof I- have hereunto set my hand before two subscribingwitnesses, this 18th day of November, 1904. JAMES F. MoELROY. Witnesses:WILLIAM A. MoRRILL, Jr.,

BE AH CABLE.

